Heat conserving system for locomotive terminals



March 13, 1934. J. E. HAWE ET AL 1,950,610

. HEAT CONSERVING SYSTEM FOR LOCOMOTIVE TERMINALS Filed Nov. 19, 1930 IN V EN TOR:

A TTORNEYS.

Patented Mar. 13, 1934 NlTED STATES PATEN F F l E HEAT CONSERVING SYSTEMFOR LOCO- MOTIVE TERMINALS Application November 19, 1930, Serial No.496,641

4 Claims. (Cl. 122-396) This invention relates to railway terminals ofthe direct steaming type, in which locomotives, employing for theirnormal propulsion steam generated by combustion of fuel upon thelocomotive grate, are filled with water at steaming temperature andsteam at propelling pressure, from a local source, so that thelocomotives while at the terminal are maintained in self propellingcondition without the presence of fire upon the locomotive grates; andwhich said terminals, for the sake of economy, have come to employgrouped apparatus and a single hot water reservoir for supplying fillingwater to the locomotives and feed water to the local steam generatorwhich charges the locomotives and operates the power plant and otherconveniences of the terminal.

When steam from a stationary power plant is supplied to locomotivesstanding in an enginehouse, to generate or maintain a working steampressure therein without fires on the grates, a new problem arises inthe economical generation of steam not encountered when stationaryboilers are employed merely for supplying steam to stationary engines,pumps, etc., it being the usual power plant practice either to condenseall exhaust steam from engines, pumps, etc. and use the condensate asboiler feed water, or to utilize this exhaust steam for heating freshboiler feed water. In either case, the heat content in exhaust steamavailable is ample to supply or elevate the temperature of the boilerfeed water to a degree considerably above the temperature of steam atatmospheric pressure.

When, however, a considerable portion of the total steam generated bythe stationary boilers at a locomotive terminal is delivered tolocomotives standing in an adjacent enginehouse without fires on thelocomotive grates, as is the practice in direct steaming systems, thenthe quantity of exhaust steam available from such stationary engines,pumps, etc. as are supplied with live steam from these stationaryboilers, may be insufiicient in heat content to supply or elevate thestationary boiler feed water to the highest degree practical for mostefiicient operation; bearing in mind that this feed water must be equalin weight to the total weight of steam supplied both to the stationaryengines from which exhaust is available, and to the locomotives fromwhich there is no exhaust steam available.

In the operation of direct steaming systems, the reservoir supply of hotwater essential for filling locomotive boilers with a mixture of hotwater and steam which enters the boiler at or above a steamingtemperature, is ordinarily heated to the appropriate degree by the steamcontent of the blow-back from locomotive boilers emptied on arrival atthe terminal. This blow-back is conveyed through a blowoff pipe from aconnection to the locomotive in the enginehouse, to a separator in whichthe steam content is disengaged from the boiler water and thenceconducted to a condenser of the jet type into which fresh cold water issprayed to condense the steam. The resulting condensate and spray waterheated by contact with the steam, drains from the condenser into the hotfilling water reservoir where it is kept stored in readiness for use.

In steaming up locomotives, either in the manner described or with afire on the grates, it is obvious that the higher the temperature ofwater with which the locomotive boiler is filled, the less fuel and timewill be required for developing a desired working steam pressure on thelocomotive; and if this filling water can be heated exclusively by meansof blown-back steam that would otherwise be wasted, it is obvious thatany increase in the temperature of filling water thus obtainedrepresents a net fuel saving in the operation of the terminal. ervoirtanks open to atmospheric pressure are the only practical meansavailable for storing a sufficient quantity of locomotive filling waterfor the operation of an ordinary terminal, it Will be seen that thisplaces a definite limitation upon the degree to which this filling watercan be heated. For instance, it is found in practice that However, aslarge ms- Whenever the filling Water thus stored in a reservoir open toatmospheric pressure, exceeds a temperature of about 200 F., it beginsto vaporize and at 212 F. it will evaporate into the atmosphere assteam.

The quantity of heat available from the steam content in locomotiveblow-backs varies considerably at different locomotive terminals anddepends largely upon the conditions under which the terminal isoperated. Thus, for instance, Where it is customary practice to holdlocomotives in the enginehouse at a working steam pressure forconsiderable periods without fires on their grates, the steam supply tolocomotives from the stationary boiler plant condenses and graduallybuilds up the water level in the locomotive boiler so that some of thiswater must occasionally be blown out of the locomotive through theblowback line. If this water is at a temperature corresponding totemperature of steam in the locomotive, it will augment the quantity ofsteam heat in the blow-back from locomotive boilers emptied at theterminal so that the total quantity of steam heat in the combinedblow-backs from the enginehouse may greatly exceed the amount of heatthat can be utilized for raising the temperature of all the fillingwater required at 200 F. Where this condition applies, the logical step,and the one that is now being widely employed, is to draw the stationaryboiler feed water from the same reservoir supply provided for locomotivefilling water so that the steam heat available from all locomotiveblowbacks can be not only applied to raising the temperature of waterfor filling locomotive boilers, but also to heating the additionalquantity of water required for feeding the stationary boilers of theterminal. At terminals where a large portion of the steam fromstationary boilers is delivered to locomotive boilers in theenginehouse, this practice tends to compensate for the inadequate supplyof exhaust steam from engines, pumps, etc. available for heating thestationary boiler feed water. For this reason, the use of a commonreservoir for locomotive filling water and boiler feed water has becomea quite general practice since the introduction of direct steamingsystems.

But since, as explained above, the temperature at which water can bestored in a reservoir open to atmospheric pressure is practicallylimited to about 200 F., and at terminals where the combined steam heatfrom locomotive blow-backs and engine exhaust is more than sufficient toraise all locomotive filling water and boiler feed water required tothis temperature, it becomes highly desirable to avoid this veryconsiderable heat loss by providing a simple and adequate method andmeans for conserving all of the steam heat available, and completelyutilizing it for heating both the locomotive filling water and thestationary boiler feed water to a temperature in excess of 212 F.Accordingly, the purpose of this invention is to provide a practical andadequate method and means for utilizing all the steam heat that may beavailable under any ordinary circumstances from locomotive blowbacks andfrom engine exhaust, for heating both the locomotive filling water andstationary boiler feed Water to a temperature substantially above thatwhich is possible of attainment in an open hot water reservoir.

The aforesaid purpose is achieved by the novel combination of waterheaters, exhaust steam distributing lines, water pumps, a hot waterreservoir, and stationary boilers, of a locomotive terminal havingsteam, filling water and blowback lines, substantially as hereinafterdescribed.

The accompanying drawing shows the preferred embodiment of the inventionby way of illustration.

In the said drawing, 1 represents a plurality of stalls in anenginehouse, equipped for receiving locomotives 2, and connecting theselocomotives up to suitable drops 3 with a blow-back line 4, a steamsupply line 5 and a filling water supply line 6. Blow-back line 4 leadsto a separator 7, whence the liquids escape through a pipe 8 to anydesired place of disposal while the volatiles rise and flow through apipe 9 to a condenser 10, the cold water sprays of which are supplied bypipe 11. Fresh condensing water and condensate pass from condenser 10 bygravity through a pipe 12 to an elevated point in the filling waterreservoir 13, which by reason of its proportions, is suitably opened toatmosphere, as, for instance, through a vent 14, and in which the hotfresh Water is stored as a supply for both the locomotives 2 and for astationary steam generator 15. A plant of this nature will also includevarious forms of apparatus which may conveniently be driven by steam,such, for instance, as a pump 16 for feeding water from reservoir 13 tothe water supply pipe 6 leading to the locomotive stalls, which pump isdriven by steam engine 17; the pump 18 for forcing Water from reservoir13 through pipe 19 to the stationary steam generator 15, which pump isdriven by steam engine 20; and such other convenience apparatus as maybe required, typified in the present instance by the steamturbineelectric generator 21, 22.

Steam pipe 5, leading to the stalls 1, is supplied by the steam header23 leading from the stationary generator 15; and this steam header willbe provided with various branches through which to supply the othersteam consuming apparatus, for instance, branch 24 leading to the engine20 of the pump which supplies the sta tionary steam generator; branch 25leading to the steam turbine 22 of the steam turbo-electric generator;and branch 26 leading to the steam engine 17 of the pump 16 which forceswater to the locomotive stalls. In order to conserve the heat exhaustedfrom these several steam consuming apparatus for use in carrying out thepresent invention, a steam manifold 27 is provided with a connection 28leading to the exhaust of the steam engine 20, a connection 29 leadingto the turbine 22, and a connection 30 leading to the steam engine 1'7;and this steam manifold is tapped into one or more heat exchangers, heretypified by the closed type water heaters 31, 32, through which arepassed, respectively, the filling water supplied through pipe 6 to thelocomotives and the feed water supplied through pipe 19 to thestationary steam generator 15. 6a in the water heater 31, and 19a in thewater heater 32, typify suitable coils or other arrangement of heattransfer surfaces located in these heaters and connected in series withsaid pipes 6 and 19. 31a, 32a represent steam traps for the disposal ofcondensate accumulating in the heaters 31 and 32 from the transfer ofheat from the steam derived from manifold 27 to the water passingthrough the coils 6a and 19a.

In order to provide for use of steam in manifold 27 in excess of thatwhich will be condensed in the heaters 31 and 32, said manifold isprovided with an outlet 33 discharging at a point 34 in the reservoir13, sufficiently submerged to impose a head of back pressure that willcause the manifold to keep the heaters 31 and 32 filled. Excess steamescaping in this way assists in keeping up the temperature of locomotivefilling and boiler feed water in reservoir 13. In the event that thesupply of water in reservoir 13 should be depleted to a point which willleave insufficient back pressure in pipe 33, a back pressure valve 35will maintain in said pipe 33 a resistance to escape of steam sufficientto insure the presence of steam in the heaters 31 and 32 at a pressurewhich will maintain the desired temperature around the water heatingcoil. Obviously, back pressure valve 35 may be adjusted so that it alonewill control the back pressure in pipe 33, and by its regulation it maybe made to vary, within limits, the pressure and correspondingtemperature within the heaters.

We claim:

1. In a locomotive terminal, a locomotive stall having a blow-back lineand a water filling line, a stationary steam generator havingconnections through which it supplies steam to said locomotive stall, awater reservoir having connections through which, respectively, itsupplies water to said filling water line and said station ary steamgenerator, independent heat exchangers through which, respectively,water so supplied fiows to said filling water line and to saidgenerator, an exhauststeam source, steam ducts through which exhauststeam from said source reaches said exchangers, and means permittingescape from said ducts of exhaust steam in excess of a predeterminedback pressure maintained on said exhaust steam source, each heatexchanger being constructed to exchange heat from exhaust steam receivedby it to the water passing through it without admixture of said steamand water.

2. A locomotive terminal as described in claim 1, in which the exhauststeam source includes a plurality of exhaust steam units connected by amanifold.

3. In a locomotive terminal, a locomotive stall having a locomotiveboiler filling line, a filling water reservoir, a water pump drawingfrom said reservoir and delivering to said filling line, a heatexchanger in said filling line, between said pump and said stall, anexhaust steam pipe communieating with said exchanger, said exchangerbeing constructed to exchange heat from the exhaust steam received by itto the filling water passing through it without admixture of said steamand said water, an escape pipe that conducts, to the water reservoir,steam in excess of that desired for the exchanger, which is permitted toescape from the exhaust steam pipe, and means for developing backpressure in said escape pipe suificient to maintain said desired steampressure in the exchanger; the last-named means consisting of ahydrostatic column of water in the said water reservoir.

4. A locomotive terminal as described in claim 3, in which thelast-named means consists of a hydrostatic column of water in the saidwater reservoir, together with a back flow valve in the said escapepipe, which said valve functions when the said hydrostatic column dropsto a level insufficient to maintain the desired steam pressure in theexchanger.

JOHN E. HAWE. LELAND G. PLANT.

